Document retrieval apparatus and method

ABSTRACT

A document retrieval apparatus and method having a plurality of movable trays each containing encoded documents which are normally stored in addressable crypts arranged in two opposed, spaced matrices with the crypt openings of respective matrices in common vertical planes, a main document selector designed to select a desired document from among a tray of encoded documents transported thereto, and a tray transport movable in the space between the crypt matrices, the main selector and the crypt openings for transferring trays of encoded documents between their respective crypts and the main selector, and a keyboard control console which in response to entry of data identifying a document in a specific tray effects the transfer of the tray from its respective crypt to the main selector whereat the desired document is then ejected by the selector from among those of the retrieved tray. A second, or buffer, selector, which is searched along with the main selector when a document is sought, is provided for temporarily storing retrieved documents prior to their return to storage, or new documents prior to infiling, in the movable trays stored in the crypts.

United States Patent 11 1 Kalthofi et a].

[ DOCUMENT RETRIEVAL APPARATUS AND METHOD [75] Inventors: Robert J.Kalthoff, Cincinnati; Richard C OBrien, Dayton, both of [21] Appl. No.:213,848

Primary Examiner-Allen N. Knowles Attorney-James S. Hight et al.

[ 1 Apr. 10, 1973 57 I ABSTRACT A document retrieval apparatus andmethod having a plurality of movable trays each containing encodeddocuments which are normally stored in addressable crypts arranged intwo opposed, spaced matrices with the crypt openings of respectivematrices in common vertical planes, a main document selector designed toselect a desired document from among a tray of en-' coded documentstransported thereto, and a tray: transport movable in the space betweenthe crypt matrices, the main selector and the crypt openings fortransferring trays of encoded documents between their respective cryptsand the main selector, and a keyboard control console which in responseto entry of data identifying a document in a specific tray effects thetransfer of the tray from its respective crypt to the main selectorwhereat the desired document is then ejected by the selector from amongthose of the retrieved tray. A second, or bufier, selector, which issearched along with the main selector when a document is sought, isprovided for temporarily storing retrieved documents prior to theirreturn to storage, or new documents prior to infiling, in the movabletrays stored in the crypts.

a Claim, 33 Drawing Figures HI 4 "lllillillmiliillihim.new

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PATENTEB APR 1 [H973 sum 13 CF 15 PATENTED APR 1 01975 SHEET 1H8? 15locate a desired card which is then available for reference, furtherprocessing, or the like.

The document retrieval apparatus and methods of this invention, while ofgeneral utility in many respects, are of particular value in connection,with automatic document selection of the type disclosed and claimed inthe patent of Robert D. Parry, US. Pat. No. 3,478,877 entitled ArticleSelection System". As disclosed in greater detail in that patent, thedocuments are edge coded with identifying information by removing, e.g.,notching, selected teeth from a bottom horizontal edge termed thesorting edge. Thereafter, a large number of documents, e.g., 2,000, arestored in a deck located in a card selector, with the sorting edges ofthe documents collectively forming the lower surface of the deck.Ferromagnetic implants, which are provided in each document, aredisposed along another edge of the document,namely, a vertical edge,designated the front edge.

In order to select a desired document or documents from the deck locatedin the selector, an operator actuates a series of keys to set up thedesired code on a series of vertically shiftable sort bars located inthe selector in a horizontal plane transverse to the sorting edges ofall documents. Certain of the sort bars enter the spaces betweenadjacent teeth in the lower edges of the document, the particular sortbars depending on the code of the desired document. A horizontal magnetcommon to all documents and movable in a direction parallel to thesorting edges is adapted to be brought into engagement with theferromagnetic implants of the documents which are aligned with respectto each other. After selected ones of the sort bars have been raisedinto the interstitial spaces of the document sorting edges, the magnetis moved away from the deck to partially withdraw all documents notrestrained by the sort bars, that is, all documents having a removedtooth pattern corresponding to the code of the desired documents.Thereafter, all the documents not initially moved are held in place by alocking bar, also transverse to, and common to, all documents, which israised into engagement with locking notches provided in the documents,while the selected and conformingly I .notched documents are furtherseparated by additional outward movement of the magnet.

To maximize the utility of a single selector system,

"which as noted is effective to simultaneously search all documents inthe single deck stored in the selector, in certain applications it isdesirable to associate with the single selector a large number ofindividual decks of documents, any one of which, while normally storedremote from the selector, can be brought to the selector for a searchoperation. In such cases, the decks of documents which in one form maybe cards are stored in individual containers or trays, the trays in turnnormally being stored remote from the selector in a bank of addressablelocations or crypts. A tray retriever movable between the selector andthe various tray crypts of the bank is provided to transport, uponcommand, a tray containing a desired card to the selector whereat thedesired card is selected from the deck contained in the retrieved tray.

In accordance with one aspect of this invention the crypts are arrangedin at least one matrix of forward and rear vertical stacks with thecrypt openings of both stacks in a common vertical plane. Locatedadjacent the crypt openings is a movable tray support for transporting adesired tray between storage in its respective crypt and a position atthe selector with the lowermost sorting edges of the cards exposedthrough the open bottom of the tray in operative relation to thesort'and lock bars of the card selector which are in a horizontal planeperpendicular to the plane of the crypt openings. The movable traysupport, in a preferred form, includes a vertical tower on which anelevator is mounted for up and down sliding movement. The elevator has ahook for engaging a tray when the elevator is aligned with its crypt andtransferring the tray between the crypt and elevator. The vertical toweris mounted on a platform which is movable between forward and rearpositions in which the tray hook of the elevator is aligned with thetrays of the forward and rear crypt stacks, respectively. In accordancewith this arrangement, the selector is located such that when the toweris in its forward position, the elevator is aligned above the selectorto permit a tray supported thereby to be deposited atop the selector asthe elevator descendson the tower.

It is essential that the notched sorting edges of the cards of a traypositioned in the selector be properly aligned with the sort and lockbars thereof which, as noted, are disposed in a horizontal planeperpendicular to they plane of the crypt opening. A unique approach hasbeen incorporated in this invention which permits proper card sortingedge and selector bar alignment and yet does so without requiringcritical positioning of the tray in the selector by the tray retriever.

Specifically, and to avoid criticality of retriever positioning in ahorizontal direction perpendicular to the plane of the crypt openings,the lengthof the selector sort and lock bars is designed to exceed thelength of the tray which is deposited in the selector by theretriever.,ln this way, and to the extent of the excess in length, thetray retriever can position the tray without criticality anywhere in ahorizontal direction perpendicular to the crypt opening plane, nd thesort and lock bars will be inoperative relationship to the sort edges ofall cards in the deposited tray.

To reduce the criticality in retriever positioning in the horizontaldirection parallel to the plane of the crypt openings, the selector isprovided with fixed locating means which the rear wall of a depositedtray can be urged against to properly position the tray (and the cardstherein) relative to the selector sort and lock bars when the elongatedselector magnet is moved inwardly prior to a selection cycle and abutsthe front vertical card edges, moving the tray against the selectorlocation means and the card notches into registration with the selectorbars. Thus, the tray and contained cards are moved horizontally againstthe locator by the inwardly moving selector magnet in a directionparallel to the crypt opening plane to produce the desired condition ofalignment between the notches of the sorting edges of the depositedcards and the selector sort and lock bars.

Finally, to reduce the criticality in retriever positioning in avertical direction, the tray supporting means on the elevator aredesigned to permit the elevator to overtravel in a downward direction asa tray supported thereby is deposited in the selector. In this way, theselector properly positions the tray and, hence, the coded edges of thedocuments contained therein, relative to the selector sort and lock barsregardless of the exact vertical position of the elevator. Of course,this assumes the elevator does overtravel at least to some degree. Thus,by virtue of the excessive lock and sort bar length, the selectorlocating member and inwardly moving magnet, and downward elevatorovertravel, the movements of the tray retriever, including that of thetower, elevator and hook, in the course of depositing a retriever trayin the selector are not critical and hence need not be controlled to ahigh degree of precision. This reduction in retriever positioningcriticality increases reliability and decreases system cost.

In accordance with another aspect of this invention, also designed tosimplify the structure and operation of the tray retriever, the verticaltower which moves between forward and rear positions is secured to ahorizontal platform mounted by a parallel linkage mechanism forpendulum-like movement between forward and rear positions. As aconsequence of the pendulum mount, very little energy is requiredto'transfer the tower between its forward and rear positions, the onlyenergy being that required to overcome frictional losses incurred as thependulum support swings through its are between forward and rearpositions.

For the purpose of automatically locating cards which may from time totime become misfiled in the trays due to human operator error, adocument detector strategically positioned in the selector, incombination with a unique card selection procedure, is utilized.Specifically, a light source and phototransducer positioned in theselector on opposite sides and toward the rear of a deposited tray areprovided to sense the existence in the deposited tray of a card whichhas not been selected, i.e., not been withdrawn from the tray, pursuantto a selection cycle. When a tray is retrieved and deposited in theselector, and the selector caused to go through a selection cycle toselect all cards hearing encoded identifying data corresponding to theaddress of that tray, a misfiled card will not be selected, but ratherwill remain fully inserted in the deck. As such, the misfiled card willbe detected by the combined phototransducer/light source detector, andan appropriate indication, such as a flashing light or the like,provided to the operator who can then manually remove the misfiled cardfor proper filing.

In accordance with another and very important aspect of this invention,a second or buffer selector is provided which is searched in parallelwith the searching of the main selector, i.e., the selector to which thetray retriever transports trays. The buffer selector temporarily storesdocuments prior to filing of such in their respective trays at periodicintervals of extended duration, e.g., once per week. For example, thebuffer selector temporarily stores all new cards which at appropriateperiodic weekly intervals are transferred to their respective trays inthe bank. Additionally, the buffer selector temporarily stores cardsawaiting further processing which have been selected by the mainselector as an incident to a tray retrieval operation. Such furtherprocessing may include updating, duplicating, or the like. Often cardsare retrieved from their respective trays by the main selector on a moreor less continuous basis throughout the day for further processing suchas duplication, updating, or the like, but the duplication or updatingis actually to be performed only at one point in the day, for example,at the end of the day. In such case, the continuously retrieved cards,upon retrieval, are transferred from the main selector to the bufferselector.

Since the main selector and buffer selector are searched simultaneouslyas an incident to any tray retrieval and search operation, if a card inthe buffer selector, previously retrieved for copying or the like at theend of the day, is desired for another purpose during the day, it willbe retrieved on command notwithstanding that it is not in its respectivetray due to awaiting copying, etc. at the end of the day. Of course,while the cards are being duplicated or updated, the cards are inneither the buffer selector nor their respective tray and, hence, arenot available for searching. However, such unavailability is not aserious disadvantage, particularly when viewed in light of the fact thatall cards in the system are available for searching during the majorportion of the day notwithstanding that during the day many will havebeen retrieved from their respective trays and stored in the bufferselector to await further processing.

These and other advantages of the invention will become more apparentfrom a detailed description of a preferred embodiment thereof in which:

FIG. 1 is a perspective view of the document storage system of thisinvention showing the relative orientation of the retrievable tray bank,main selector and buffer selectors;

FIG. 2 is a diagrammatic perspective view, partially broken away, .ofthe retrievable tray arrays, tray retriever and main selector;

FIGS. 3, 4, 5, 6, and 7 are diagrammatic cross-sectional views showingthe relationship of the elevator and tray hook, crypts, and trays invarious stages of storage in their respective crypts, on the elevator,or in intermediate positions of transfer between crypt and elevator;

FIGS. 3A, 6A, 6B and 6C are diagrammatic crosssectional views showingdetails of the crypt, tray and elevator;

FIG. 8 is a plan view of the tray bank, tray retriever, and mainselector, showing a tray supported by the elevator;

FIG. 9 is a front elevational view of the crypt array, tray retriever,and main selector showing a tray supported by the elevator;

FIG. 10 is a cross-sectional view taken along lines l0-l0 of FIG. 8;

FIGS. 11 and 12 are side elevational views showing the tower platformmoving toward its rear and forward positions, respectively;

FIG. 13 is a cross-sectional view taken along lines 13-13 of FIG. 9;

FIG. 14 is a front elevational view of the lower portion of the trayretriever;

FIG. 15 is a cross-sectional view taken along lines l5l5 ofFIG. 9;

FIG. 15A is a perspective view of the elevator, crypt level detector,and associated crypt level flag;

FIG. 16 is a cross-sectional view taken along lines 16-16 of FIG.

FIG. 16A is a perspective view, partially exploded, of the tray hook andmotor;

FIG. 17 is a cross-sectional view taken along lines 17-17 ofFIG. l6;

FIG. 18 is an elevational view of a portion of the main selector showinga tray being deposited on the platen by the elevator;

FIG. 19 is a plan view, partially broken-away, of the tray;

FIG. 20 is a front elevational view, partially brokenaway, of the tray;

FIG. 21 is a cross-sectional view of the tray taken along lines 21-21 ofFIG. 20;

FIG. 22 is an elevational view of an alternative form of pendulum towersupport;

FIGS. 23A-23E are schematic perspective views of a selector showing therelationship of the cards, platen, sort and lock bars, and movablemagnet during different stages of a card selection cycle.

For the purpose of more easily understanding the retrieval method andapparatus of this invention, the invention is described in connectionwith card selection of the general type disclosed in Parry US. Pat. No.3,478,877, the entire disclosure of which is specifically incorporatedherein by reference. The Parry selector 8, as shown schematically inFIGS. 23A-23E, includes a housing 13, a stationary horizontally disposedplanar platen 20 which supports a deck of randomly stored, verticallydisposed cards 22, a transversely disposed elongated magnet 24 common toall the cards 22 and in alignment with ferromagnetic chips 23 implantedin the leading edges of the cards is secured to a drawer-like structure26. The drawer 26 is mounted to housing 13 for sliding movement betweenan outer position (FIG. 2315) to which desired cards 22a are advancedfrom the deck by the magnet 24 in a manner to be described, and an innerposition (FIGS. 23A, 23B) in which the magnet 24 is in contact with theferromagnetic card implants 23 when the cards are stored in their normalposition on the platen 20. Multiple card decks related respectively todifferent subject matter may, in conjunction with a single selector 8,comprise a card storage system. However, in such a multideck/singleselector system, only a single deck of cards can be placed in theselector at any given time for card selection purposes, the other decksbeing stored remote from the selector.

As best seen in FIGS. 23A-23E, the cards 22 each have a toothed sortingedge 32, preferably the lower edge thereof, provided with alternateteeth 34-1 to 34- 6 and registration notches 35-1 to 35-6. Each of theteeth 34-1 to 34-6 is susceptive of being encoded in binary by selectiveremoval, as by notching, of the tooth. While only six teeth 34-1 to 34-6have been shown along sorting edge 32, for the sake of convenience, in atypical installation the cards 22 are each provided with 60 encodableteeth which, when divided into 12 groups of five teeth each, can beutilized to encode l2 characters, for example, letters and/or numeralsin a conventional two-out-of-five code format. Two of the characters canthen be utilized to represent the address in binary-coded-decirnal formof the particular deck 22 of a multi-deck storage system in which thecard is typically stored, while the remaining ten characters can beutilized to further identify the card with respect to the othercardsstored in that deck. The sorting edge 32 further includes a locknotch 36 located between the group of encodable teeth 34 andregistration notches 35, and the transverse card edge 38 herein termedthe.

trailing edge. Adjacent to the lock notch 36 Y is a removed portion 40of the card located intermediate the lock notch 36 and the trailing edge38. The card 22 further includes the ferromagnetic chips 23 implanted inthe card to the corner of the sorting edge 32 and a transverse edge 44herein termed the leading edge".

When the cards of a deck located in the selector 8 are in their normalunselected position on the selector platen 20, the registration notches35-1 to 35-6 and the lock notch 36 are aligned with a plurality oftransversely disposed sort bars 48-1 to 48-6 and the lock bar 50 whichare disposed transverse to, and in common with, all the cards. Both thesorting bars 48-1 to 48-6 and the lock bar 50 are appropriatelypositioned in slots formed in the upper surface of the platen 20. Thebars 48-1 to 48-6 and 50 are elevatable vertically from a reset positionwherein their upper edges thereof are flush with the upper surface 20aof the platen 20, to a set position wherein the bars extend above platensurface 20a and enter their associated notches 35-1 to 35-6 and 36,respectively, of cards located in the storage position. Elevation of thebars 48-1 to 48-6 and 50 is effected by solenoids (not shown) controlledby a keyboardzconsole (also not shown).

Assuming a deck of cards 22 is properly located on selector platen 20,to select a card or cards 22 having a particular code, for example, acard 22a from the deck having teeth 34-2 and 34-6 removed, from among agroup of cards 22b in the deck not having teeth 34-2 and 34-6 removed,the appropriate sort bars 48 are elevated above the platen surface 200to the set position. Specifically, sort bars 48-2 and 48-6 correspondingto the removed tooth pattern of the desired card 22a are elevated to theposition shown in FIG. 238. With thesort bars 48-2 and 48-6 in a setposition, the desired cards 22a having teeth 34-2 and 34-6 removed canbe laterally shifted in the direction 46a of arrow 46 a distance equalto the width of one tooth, to producev an initial separation of thedesired cards 22a in the deck of cards 22 from the undesired cards 22b.However, the undesired cards 22b not having tooth 34-2 and/or tooth 34-6removed are restrained from lateral movement in the direction 46a ofarrow 46 by one or both of the set or elevated sort bars 48-2 and 48-6,which, in the set position, mechanically interfere with the unremovedteeth 34-2 and 34-6 of the undesired cards 22b.

With the sort bars 48-2 and 48-6 conforming to the removed tooth patternof the desired card 22a in the set position, the drawer-mounted magnet24 is shifted in the direction 46a of arrow 46 a distance equal to thewidth of one tooth to the position shown in FIG. 23C. Those cards freeto shift, namely, the desired cards 22a move with the magnet 24 adistance of one tooth width, effecting an initial separation of thedesired and undesired cards. Movement of the desired cards 22a in thisfashion aligns the removed portion 40 of the desired cards opposite thelock bar 50. The undesired. cards 22b do not move in the direction 46aof arrow 46 by reason of the engagement of one or more of theirunremoved teeth 34-2 and 34-6 with the set sort bars 48-2 and 48-6,respectively. Consequently, the lock notches 36 of the undesired cards22b remain aligned with the lock bar 50. At this point the initial phaseof the card selection operation is complete.

Further separation of the desired cards 22a from the undesired cards 22bof the deck 22 to effect the final card selection phase of the retrievaloperation is accomplished by elevating to a set position the lock bar50, and returning to an unset position the sort bars 48-2 and 48-6, asshown in FIG. 23D. Setting lock bar 50 positively prevents the undesiredcards 22b of the deck 22 from moving in response to the continuedmovement of the magnet 24 in the direction 46a of arrow 46. Resetting orlowering the set sort bars 48-2 and 48-6 after the initial cardseparation phase enables the selected cards 22a to continue movement inthe direction 46a of arrow 46 in response to movement of the magnet 24in this direction by reason of the removed portion 40 thereof beingaligned with the elevated or set lock bar 50. With the lock bar 50 setand the sort bars 48 all in their lower, reset position, the magnet 24is advanced further in the direction 46a of arrow 46 to the positionshown in FIG. 235, further separating the desired cards 22a from theundersired cards 22b. At this point, the final card selection phase ofthe retrieval cycle is complete, marking the completion of the cardretrieval operation.

The document retrieval system of this invention, of which the cardselector 8 (FIGS. 23A-23E) constitutes an important element in thepreferred form thereof shown in FIGS. 1 and 2, includes in addition to aselector 8-1 of the type described in connection with FIGS. 23A-23E, amass memory or document bank 60 of addressable card decks 22, eachgenerally similar to the card deck 22 described in connection with theselector 8 of FIGS. 23A-23E. The card decks 22 are stored in individualtrays 11, to be described later. In a preferred form of bank 60, thereare 60 trays 11 arranged in four stacks of 15 each. The card trays 1 1can be retrieved, in a manner to be described, under control of thekeyboard console by appropriate entry of a twodigit tray address, andtransported to the stationary card selector 8-1 which, as noted, issubstantially identical to the card selector 8 described previously inconnection with FIGS. 23A-23E. The trays 11 of document bank 60 containdocuments which are encoded in much the same manner as described inconnection with cards 22 located in selector 8 of FIGS. 23A-23E, andonce retrieved and positioned within the selector 8-1 are searched toeject the desired card, such as card 22a-l of deck 22-1 in much the samemanner as cards 22a of deck 22 were selected in connection with thedescription of FIGS. 23A-23E. Following selection of a card 22a-l from adeck 22-1 ofa retrieval tray 11-1 in selector 8-1, the tray is returnedto its appropriate storage position within the document bank 60, in amanner to be described.

The system of this invention as shown in FIG. I, further includes twoindependent buffer selectors 8-2 and 8-3, each having associated with ita tray 11-2 and ll-3 of cards 22-2 and 22-3 encoded in the mannerdescribed in connection with FIGS. 23A-23E. While only two bufferselectors 8-2 and 8-3 are shown, the quantity of such independent bufferselectors can be more or less than this number. The buffer selectors 8-2and 8-3 and associated trays l l-2 and 1 1-3 of cards 22- 2 and 22-3 aresubstantially identical to selector 8-1 and its tray 11-1 of cards 22-1.The independent buffer selectors 8-2 and 8-3 search their respectivetrays ll-2 and ll-3 of encoded cards 22-2 and 22-3 simultaneously withthe searching of cards 22-1 of tray 11-1 located in selector 8-1. Thetrays 11-2 and 11-3 of selectors 8-2 and 8-3 in whole or in part, can bedivided into compartments for holding cards with respect to whichspecific functions are to be carried out.

For example, tray 11-2 of selector 8-2 in its entirety may be utilizedfor temporarily holding, such as for a day or week, new cards which areultimately to be stored in bank 60. By temporarily storing new cardswhich are ultimately destined for bank 60, in the buffer selector tray11-2 of buffer selector 8-2, such temporarily stored new cards areavailable for search and selection notwithstanding that the new card hasnot yet been positioned in its particular tray 1 I normally stored inthe bank 60. For example, if a new card destined to be stored in a tray11 contained within the bank is first inserted in tray 11-2 of bufferselector 8-2 and such new card sought to be retrieved by entry of itsaddress in the keyboard 10, the card will be selected even though notyet in its own tray. The only difference between selection of a new cardtemporarily stored in the tray l1-2 of buffer selector 8-2 is thatselection of the new card is manifested by its ejection from the cardtray 11-2 of the buffer selector 8-2, rather than from the retrievedtray ll-l located in the selector 8-1 where the new card will ultimatelybe filed and which was retrieved from its storage position within thebank 60 and transported to the selector 8-1 as a consequence of entry ofthe card address in the console 10. In a similar manner, other bufferselector trays, such as tray ll-3 of buffer selector 8-3 can bededicated .to temporarily holding cards retrieved from bank 60 withrespect to which other functions are to be performed. For example,buffer selector tray 1l-3 of buffer selector 8-3 may be divided intocompartments 1l-3A, 11- 3B, ll-3C, and 11-3D into which cards retrievedfrom bank 60 are temporarily stored while awaiting duplication, copying,updating, or refiling in the document bank 60. In certain systeminstallations the cards 22 stored in trays ll of the document bank 60must periodically be retrieved and copied. Often the actual copying ofcards retrieved from the document bank 60 in a given day will be made atone time, e.g., at the end of the day, while the system operator mayactually retrieve the cards from the document bank 60 which are to becopied intermittently throughout the entire day. As the cards to becopied are retrieved from the document bank 60 and presented to theoperator by the selector 8-1 as a consequence of retrieval and searchingof the trays 11-1 brought to selector 8-] containing the cards to becopied, the operator places the retrieved cards in the copy compartmentll-3B of buffer selector tray 11-3 of buffer selector 8-3. At the end ofthe day the retrieved cards to be copied, which have been placed incompartment 1 l-3B, are removed and copied. Following this the cards areplaced in the re-file compartment 1 L38.

Eventually, the cards in the duplicate, copy, and update and re-filecompartments 11-3A through l1-3D of

1. Apparatus for retrieving stored documents comprising: a plurality ofgroups of documents encoded with identifying data in accordance with apredetermined code, storage means for normally storing each of saidgroups in storage locations, a first document selector located at afirst location remote from said storage locations, said documentselector operable in a selection cycle to select a document from among agroup of documents thereat which are normally stored remote therefrom insaid storage locations by said storage means, means for retrieving agroup of stored documents and depositing said retrieved group ofdocuments at said first selector for document selection thereby, asecond document selector located at a second location remote from bothsaid first selector and said storage locations, said second selectornormally containing documents encoded with identifying data inaccordance with said predetermined code, said second document selectoroperable in a selection cycle to select a document from said documentselector operable in a selection cycle to select a document from saiddocuments contained thereat, and control means for receiving theidentity of a desired document presumedly located in a specified one ofsaid stored groups and, in response thereto, operating said retrievingmeans to transport the documents in said specified group to said firstselector and effecting selection cycles at said first and secondselectors to select said desired document from among the documents atsaid selectors.
 2. Apparatus for retrieving stored documents comprising:a plurality of trays each containing stored documents encoded withidentifying data in accordance with a predetermined code, a plurality ofstationary storage crypts for normally storing each of said trays atdifferent addressable storage locations, a first document selectorlocated at a first location remote from said tray storage crypts, saiddocument selector operable in a selection cycle to select a documentfrom among a plurality of documents thereat normally stored in a trayremote therefrom in one of said storage crypts, a tray retriever forretrieving a tray from a selected one of said crypts and depositing saidtray at said first selector for document selection thereby, a seconddocument selector located at a second location remote from both saidfirst selector and said tray storage crypts, said second selectornormally containing documents encoded with identifying data inaccordance with said predetermined code, said second document selectoroperable in a selection cycle to select a document from said documentscontained thereat, and means for receiving the identity of a desireddocument presumedly located in a specified one of said stored trays and,in response thereto, operating said retrieving means to transport saidone tray and documents contained therein to said first selector andeffecting selection cycles at said first and second selectors to selectsaid desired document from among the documents at said selectors.
 3. Amethod of processing documents comprising the steps of: encoding aplurality of groups of documents with identifying data, randomly storingsaid encoded document groups in individual crypts positioned at separateaddressable locations, generating signals correlated to the identifyingdata of a desired document, transporting, in response to said signals,the group of documents in which the desired document is presumed storedfrom its crypt to a first document selector adapted to select thedesired document from the group thereat in the course of a selectioncycle, initiating selection cycles in said first selector and a secondselector which is also adapted to select a desired document from among aplurality of documents encoded with identifying data which aretemporarily stored thereat, transferring the desired document selectedfrom said transported group at said first selector to temporary storagein said second selector, and returning the documents in said secondselector to storage in their respective crypts with their respectivegroups of documents following temporary storage in said second selectorfor a period including multiple card selector selection cycles.
 4. Themethod of claim 3 further including the step of subjecting desireddocuments selected by said first selector to a processing stepexternally of said selectors intermediate the steps of selection of saiddesired document by said first selector and return of said desireddocument to storage in its respective crypt.
 5. The method of claim 3wherein said returning step includes successively generating signalscorrelated to the identifying data of different document groups,successively transporting, in response to said successive generation ofdocument group identifying signals, said groups of documents to saidfirst selector, successively initiating selection cycles in said secondselector to successively select from documents stored thereat documentsbelonging to said different groups, and successively transferring thedocuments selected by said second selector to their respective documentgroups successively transported to said first selector while said groupsare at said first selector.
 6. The method of claim 5 wherein saidreturning step further includes successively initiating selection cyclesin said first selector to successively select from document groupssuccessively transported thereto all documents properly stored in saidgroups, successively detecting documents unselected during saidsuccessive first selector selection cycles, and removing said unselecteddocuments from said groups while said groups are in said first selector.7. A method of processing documents comprising: encodinG a plurality ofgroups of documents with identifying data, randomly storing said encodeddocument groups in individual crypts positioned at separate addressablelocations, successively generating signals correlated to the identifyingdata of a different document group, successively transporting, inresponse to said successive generation of document group identifyingsignals, said groups of documents to a first selector, successivelyinitiating selection cycles in a second selector to successively selectfrom documents stored thereat documents belonging in said differentgroups, successively transferring the documents selected by said secondselector to their respective document groups successively transported tosaid first selector while said groups are at said first selector,successively detecting documents unselected during said successive firstselector selection cycles, and removing said unselected documents fromsaid groups while said groups are in said first selector.
 8. Apparatusfor retrieving stored documents comprising: a plurality of groups ofdocuments encoded with identifying data in accordance with apredetermined code, storage means for normally storing each of saidgroups in storage locations, a first document selector operable in aselection cycle to select a document from among a group of documentsthereat which are normally stored remote therefrom in said storagelocations by said storage means, means for retrieving a group of storeddocuments and operatively positioning said retrieved group of documentsand said first selector for document selection thereby, a seconddocument selector normally containing documents encoded with identifyingdata in accordance with said predetermined code, said second documentselector operable in a selection cycle to select a document from saiddocuments contained thereat, and control means for receiving theidentity of a desired document presumedly located in a specified one ofsaid stored groups and, in response thereto, operating said retrievingmeans to operatively position the documents in said specified group andsaid first selector and effecting selection cycles at said first andsecond selectors to select said desired document from among thedocuments at said selectors.